CVE-2007-4321 Affecting fail2ban package, versions <0.8.0-4


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
5.75% (93rd percentile)

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  • Snyk IDSNYK-ECHOLATEST-FAIL2BAN-20877229
  • published13 Oct 2026
  • disclosed14 Aug 2007

Introduced: 14 Aug 2007

CVE-2007-4321  (opens in a new tab)

How to fix?

Upgrade Echo:latest fail2ban to version 0.8.0-4 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream fail2ban package and not the fail2ban package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

fail2ban 0.8 and earlier does not properly parse sshd log files, which allows remote attackers to add arbitrary hosts to the /etc/hosts.deny file and cause a denial of service by adding arbitrary IP addresses to the sshd log file, as demonstrated by logging in via ssh with a client protocol version identification containing an IP address string, a different vector than CVE-2006-6302.

CVSS Base Scores

version 3.1